L.Brown,
The 12/20 was patented by William Baker, in my opinion the most inventive gunmaker ever, and offered by various firms, including Stephen Grant, under different model names. The location of proving is no guarantee of the location of manufacture. Note that no maker credits the inventor with a small stamp for this action or other Baker patents used.
Shotgunlover: You just moved the goalposts from your previous post. You weren't talking about 12/20's in general. Rather, your reference was to the LANCASTER 12/20. If you have some evidence indicating that all LANCASTER 12/20's were made in Birmingham, please present it to back up your previous statement. Otherwise, probably wise to admit that you overstated your case in favor of guns made in Birmingham.
Originally, a "best" British gun had to be London-made. Of course that can be disputed, and some makers did indeed dispute it. But the top London makers did a pretty good job of selling that concept to the public.
